Re-using used plastic material is often referred to as recycling of plastic waste material. It comprises use of post-industrial waste (material which is generated in the course of an industrial manufacturing process) as well as post-use waste (manufactured material which have been used and disposed). Recycling has advantages. For instance: less “virgin” raw materials are needed, less use of water is needed, and less energy is needed, as compared with producing plastic material for its first use. Also harmful emissions into air, water and soil, as well as any detrimental impacts on human health, may be minimized if plastic waste material can be recycled.
However, it is possible that in its previous use, plastic waste material has become contaminated with other materials. This applies particularly to plastic materials used by consumers, and disposed as waste material. In an attempt to optimize recycling processes, efforts are often made to selectively mix materials, or remove materials, so as to optimize the suitability of the recycled material for its next usage. With this objective in mind, recyclers use various known techniques like: manual sorting, sinking-floating in tanks, metal sorting techniques, wind sifting, electrostatic sorting, melt filtration, etc. Despite these sorting and mixing techniques, the plastic materials resulting from the recycling have material characteristics which tend to vary widely.
Many products made of plastic, like pipes, window profiles, etc., require material characteristics within specific and relatively narrow ranges to guarantee that the (semi)finished products will fulfil their product standards. The properties of used plastic materials, particularly post-consumer materials, vary currently still too much to allow for optimal re-use of such materials. This inhibits the feasibility of mechanical recycling of plastic waste. Processing such materials to further obtain a better quality, is often still too expensive for a low end application.
For this reason, incineration or landfill is often still the only economical way of disposing of such waste material, even though it is from an environmental point of view highly undesirable.
The present invention aims to provide a simple and straightforward method and system that allows for more economically and environmentally acceptable use of plastic material waste.